DE1622864A1 - Reflection-free screen - Google Patents

Description

PATENT ADVOCATE. Jl \ Expl DR. QUARDER ι, ¥ _

STUTTGART

Richprd-Wogner-Stroee 16 1622864

Telephone 244446

January 25, 1966

,! EHHAITl Ltd.
Hollinwood-Lanoashire (England)

Patent and auxiliary brewing sample registered in Germany

Password t screen

A 10 390 "■

4 / K

Non-reflective screen

The invention "relates to a screen with a front and a rear surface, on the rear surface of which an optical image can be formed through the front Area is considered.

In the description, the term "viewer" is to be understood in such a way that it does not only refer to human viewers but also indirect means of exposure such as television and photo cameras.

One of the main problems encountered with the "use of screen

* _ »This kind of thing arises is the mirror reflection from on

"- * ambient light falling on the front surface of the screen.

^ This problem can be solved by removing the front surface of the screen is made non-reflective β However, it is often necessary to pass the screen through a

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Layer of transparent material such as glass or plastic to protect and there are then reflections from the Surface of this protective layer is created »

It is the object of the present invention to obviate the above problem and make it anechoic Create screen *

This object is achieved according to the invention in that the screen has a plurality of light-transmitting fibers whose longitudinal axis is essentially parallel to one another, and that each fiber consists of a core of essentially transparent material which is coated with a material over its surface in the longitudinal direction , the refractive index of which is lower than that of the transparent material, and that the lines are arranged with their longitudinal axis inclined at least at an oblique angle with respect to the observed surface of this screen, so that an image \ is visible through the front surface of the screen ο -;

Further details about the invention emerge from the now the following description of an embodiment in conjunction with the drawing. This shows a partial cross-section a cathode ray tube whose screen is equipped according to the invention.

j The cathode ray tube 10 has a conventional envelope (Piston) 11 with a phosphor layer 12 on the faceplate 13. This faceplate 13 consists of a very

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large number of short optical fibers 14 »the better Explanation are shown in exaggerated size. The Aohsen of these lines run parallel to each other and at an angle to the two surfaces of the faceplate. These The inclined position of the fibers is also shown exaggerated. The manufacturing process of such a faceplate is not Subject of the invention, as this is the production method of Face mounts with fiber axes perpendicular to the faceplate surfaces. For the production of the fibers 12, any previously known method is suitable. In general, each fiber consists of a glass core or of similar material with a high refractive index and is covered with a layer of glass or similar material with a refractive index lower than that of the. Core material »Many variations are possible here e.g. the core of each fiber can be made of Phogphersiatsrial b ^ st

The screen works as follows! Through the phosphor layer, an optical image is generated, and the faceplate 13 'thus appear on the inner surface of the light travels through the .Fasern 14 to the front surface of the face plate, wherein the angle of each fiber end which causes a prism effect · _# This contact the light rays 15 from the faceplate at a more oblique angle than the slope of the fibers. The image must be viewed in a direction which is essentially parallel to the exiting light rays 15. "Ambient light impinging on the front surface of the faceplate from" any direction other than that indicated by an arrow at 16 is removed from the field of view

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be reflected away. This applies in particular to the light, that is reflected from the conveying surface of a "viewer", • This is often the cause of reflections when the screen is viewed perpendicular to its surface.

When the screen forms the faceplate of a cathode ray tube, it is often covered with a flat layer of glass, to achieve vacuum density. Reflections of this glass layer are caused in the same way by the action of the Oblique viewing is reduced and there is no perceptible image distortion when the glass layer is thin.

Although the description relates to the faceplate of a cathode ray tube, the screen according to the invention can also very good for simple optical projections to be used. As above, this creates an optical image on the back of the screen and along the fibers 14 forwarded.

When the two opposing surfaces of the faceplate 13 are parallel, no image distortion occurs however, the two surfaces are not parallel, the image is disturbed in the form of foreshortening or lengthening distortion in the direction of the slope of the fibers. The two surfaces should therefore preferably be parallel to one another.

When viewing the image on the screen in a direction substantially perpendicular to the surface of the screen should, 'a prism can be used to determine the slope of the

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To compensate light rays emanating from the screen. The prism itself also reduces the mirror reflections of the observed surface pes the screen ₀

The angle of inclination of the fibers to the faceplate of the The tube is adjusted so that it has the mirror reflections on a minimum, reduced This depends on the purpose for which the screen is used »

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Claims (1)

A 10 390 . -6- 1/25/66 AIS PROPOSALS Screen with a front and a rear surface, on the rear surface of which an optical image is generated can, which is viewed through the conveying surface, characterized by that the screen has several known light-transmitting fibers, which with their longitudinal axis run substantially parallel to each other, that each fiber consists of a core of substantially transparent material consists, which is coated over its surface in the longitudinal direction with a material whose refractive index is lower than that of the transparent material, and that the fibers are considered with their longitudinal axis at least with respect to Surface of this screen are arranged at an oblique angle, so that an image is visible through the front surface of the screen will" Screen according to Claim 1, characterized in that its anterior and posterior surfaces are parallel to each other " Screen according to Claim 1 and / or 2, characterized in that it forms the screen of a cathode ray tube. Screen according to at least one of Claims 1 to 3, characterized in that the core of each of the said fibers consists of a phosphor material. BATH ORIGINAL